Sluice box



6 Sheets Sheet l Feb. 23', T943. F. J. w. HoLT ETAL SLUICE BOX Filed Nov. 9, 1939 PIII' .r vlllll..

Feb. 23, 1943. F. J. w. HOLT 4ET Al.

SLUICE BOX 6 Sheets-Sheet 2 Filed Nov. 9, 1959 SH auw WM n www@ M Q mwomu; -Tw .m U r... .www A kx@ k x m N m m www@ y n o C u m uw m B m w@ EN w) KX w w w PL L3M v c Am\ sus. NSB MNB ww xm ww Q ww ww Feb. 23, 1943. F; 1 W HOLTKET AL v 2,312,096

' SLUIGE BOX Filed Nov. 9, 1939 6 Sheets-Shee'l 3 Feb. 23, 1943. F. J. HOLT ETAL SLUICEl BOX Filed Nov. 9', 1939 6 SheetS-Sheet 4 \NVENTO5S |T d r ...ull o u MMM, 0 O mmm, .m f A OQSA Wma eHw .MUM Inn SU .mmm Aw a l Fb. 23, 1943. F. J. w. Hour E-rAL sLuIcE Box Filed No'v. 9, 1939 e sheets-Sheet 5 @n f a4 a 5 f 'd j 2 I J7 ,l /fyf 'ff Feb. 23, 1943.

F. J. w. Hom'y ETAL SLUICE BOX- Filed Nov. 9, 1939 6 Sheets-Sheet 6 Francis'oinewarmol Au usi' UH Her) man erThomus H INVENTOR S B Y y '(L.; A'rroRNEY I Patented Feb. 23, 1943 sLI'JIcEJBoX Francis Jaime Wormald Holt, Santo Amaro, Sao Paulo, August Ullmann, Sao Paulo, and Herbert Thomas Honnor, Santos, Brazil Application November 9, 1939, Serial No. 303,640 In Great Britain November 21, 1938 4 Claims. (Cl. 209-437) This invention relates to reciprocating sluice boxes.

The chief object of the present invention is to provide a completely automatic reciprocating sluice box for the continuous concentration of minerals Which, when once set for operation with a given mineral, does not require any attention, nor does it require any additional Wash water or back pumping.

Another object of the invention is to provide a simple, compact `and highly efficient machine of high capacity which is capable of automatically and continuously classifying and concentrating minerals irrespective of their different specific weights and varying individual volumes.

Still another object of the invention is to eliminate the necessity of classifying material to a definite mesh by separate classifyingmachines before passing the same to the concentrating machines.

A particular object of the invention is to provide a sluice box which is more efficient in use and more economical in operation than previously proposed sluice boxes.

A further object of the invention is to provide novel means for removing the mineral concentrates, which means does not depend on gravity along for its proper operation and which may be adjusted to meet requirements such as varying particle sizes and specic Weights.

The sluice boX according to the present invention comprises an inclined table divided into sections comprising a plain portion of constant width constituting a settling plane, and a portion having a part of increasing depth and preferably diminishing Width, constituting a concentrating plane, mineral removing means, preferably adjustable and preferably, also, rotatable, being situated at the portion of greatest depth, and means for reciprocating the table.

Means are conveniently provided for altering the inclination of the table.

It is preferred that the means for removing mineral concentrates be such that no appreciable quantity of Water is taken from the table. In the preferred form of the invention the concentrates removal means comprises a rotating brush rotating in a direction opposite to that of the flow of the wash water and so mounted that the periphery thereof may extend above' the surface of the table to a variable extent. This brush is conveniently intermittently rotated, asby a ratchet and paWl mechanism, but it may be continuously rotated.

Below the surface of thertable in the neighrconcentrates Without appreciable loss of Wash water. In an alternative arrangement there is provided acontainer having a sloping bottom terminating in a pair of outlet ports provided with shut-ofi means such that when one port is `shut the other is open. The outlet ports are .individually connected by lengths of flexible hose or the like to collecting tanks. The container 'hoses and collecting tanks are vall lled with waterto avoid drawing from the Wash water.

IConcentrates collected by the brush are carried down into the container Where they are Washed off by the disturbance of the Water in the con- 'tainer and, then, fall down and pass out through -one of the ports and so into one of the tanks. YWhen that tank is full the closure means are reversed whereupon the iilled tank may be removed for emptying or replacement by an empty 'tank which is filled with Water before being connected to the hose leading to the container.

In order that the invention may be clearly understood and readily carried into effect, constructional embodiments of the invention are hereinafter more fully described by Way of example With reference to the accompanying draw- 'ings which are given for the purpose of illustration but not limitation. In these drawings- Figure 1 is a plan of `a portion of the machine having the table partly broken away to expose the driving mechanism.

Figure 2 is a side elevation of Figure l. Figure 3 is a plan of another portion of the machine having the table partly broken away to expose the re-coil springs.

Figure 4 is la side elevation of Figure 3.

Figure 5 is a section online 5-5 of Figure 3.

Figure 6 is a transverse' section, partly in elevation, of means different from those shown in Figures 1 to 5, for dealing with the concentrates.

Fig. '7 is a vertical longitudinal middle section through a device, as shown in Fig. 6, and

Fig. 8 is a side elevation of an adjustable sup- In practice, it is Convenient to triplicate the set of apparatus comprising the settling and concentrating planes, together with the means for collecting andremoving the concentrates and the .attendant mechanism, to form a single machine,

vfixed plate h6.

are vertical and have affixed along their length, a

strip of metal a2 which overhangsthe concentrating plane. At the lower end of the concentrat- A ing plane is provided an aperture a3 through which protrudes a portion of the periphery ofafrotary collecting brush (hereinafter referredto).V *Deiiector plates a4 are xed to the table surfaceand an adjustable plate a5 (at the tailing edge of the brush) is mounted sothat it `can slide-upon and be locked to them. `The deectorplates and the sliding plate prevent theentr'y of gangue down the sides of and behind the brush. Y

They table is mounted on channel side members b supportedy on'wheels b1 which in 4turn are sup-..

ported on'rails c. The whole machine is given an even to and fro motion by means of a connecting-'rod d connected at one'end to a rod b2?v supported in a bracket bfixedfto the side-members b and at the otherV end to an adjustable out-ofcentre position of-male and female grooved-faced crank-webs d1 on a shaft d2 driven from any suitable source by a belt d3. The crank-webspermit of adjustment ofthe stroke of the connecting rod. 'Re-coil springs e (seeFigures 3, 4, and 5) are mounted under compression against stationary brackets e1 on either side Vof theY front axle b4 of thernachine, and when they areequally'adjusted they tend'to throwthe machine'backward and forward uniformly, thus relieving'thetablesurface of shock, preventing undue disturbance of the layer of concentrates and taking up any backlash that may develop in the drive. v

The collecting brush shown .at f, is mounted on a shaft jfl running `through 'arcuate slots formed in the side walls ofthe container g' which latter is secured in 'a water-tight manner to the underside of the sluice-.box. The arcuate slots are made water-tight by means of rubber and steelwashers tightened by screw-glands as shown at g1 (Figure 5). 'Ihe shaft f1 is' hung on radius arms h whose upper pivotal points are in alignment with the contact line of the brush with the tailing edge of the concentratingplane a1. 'The lower ends of the arms h areconnected to rods h1 which in turn are connected to a ,shaft h2 mounted in bearings h3. lA handle h4 enables the shaft h2 to be moved. angularly for the purpose of raising and lowering thebrush in the aperture a3 with the periphery of the brush always in contact withV the tailing edge ofthe concentrating plane. VThe brush having been adjusted in position it is prevented frornmoving accidentally by means of a spring-loaded'locking pin h5 engaging in one of arseries of holes in a The upper pivotal points of arms h are mounted on plates h' (Fig. 8) which are in vturn mounted onthe channel'side members `b and are adjustable in a vertical direction by means of set screw l1,8 and slots hg. The adjustable plate a5 is movedfnearer toorl further fromfthev said Atailing edge so that it willterminate at or close tothe periphery of the brush Ieach 'time'that the :position of thelatter has been adjusted. The

brush is given an intermittent rotary motion against the flow of water down the table by means of a double-acting pawl i pivoted on an arm jl and acting on a ratchet wheel 92 fixed on the shaft f1 carrying the brush. The ratchet wheel is driven by the link 7'3 connected to the bar i4 mounted in guides b5. The bar 74 is reciprocated by means of a rotary crank i5 xed to one or other of the shafts i6 of reduction gears (not shown) enclosed in a casing :i7 and geared to the shaft d2 the crank being connected to the f.bar 7'4 through link f, arms i9 and 710, link 7'11, ,bell-crank 712 and link 7'13, number vofratchet-wheel teeth taken per stroke is "achievedby varying the position of the link 9'11 Adjustment of the along the arm 710. Different speeds of rotation :of the` crank i5 are obtained by fixing it to the kappropriate shaft i6.

straight line, thereby-not affecting the ratchet wheelmovement. AVifhen adjusting the inclination of-themachine, the lock-nut filconnecting vthe link 7'11 totheLbell-crank i12 is slackened to allowr thecorresponding Vend of the be1l-crank to take up a new position along thevslot in the link 7'l1 The concentrates are automatically removed from the container g bymeansA of 'afconveyor screw k rotating in `a casing k1 and whose outlet k2 is arranged above the table'so-'that-no'appreciable quantity of Water-is lost. The conveyor is vdriven vby-a'shaft-lc3 (Figure 5) andgearing k4 and K5, theshaft k3' being common' to the driving Vgear of the conveyors-of all the containers and being driven'by any'suitable means suchas'an electric motor (not shown) `mounted on channel member b at one end thereof.

"In an alternativeconstruction (see "Figure 6) for the'removal of the concentratesythe container Z is provided with -a pairf of outlets l1' controlled by valves Z2 and connectedI by 'flexiblehose's' to stationary collecting tanksl4 `which ^are `initially full of `vvater'to .prevent drawing ioff any u'of 'the kwash water from 'the'table. "When one Yof the `tanks 14; is`full the corresponding'valve sclosed,

the enjd 'of' the corresponding those is. disconnected from v.the tank'and the' tank4 is removed and'replaced by another tankiiiilled with water.

The inclinationofthemachine is'adjusted by `a simple left and VVrightiiand'threaded screw m and scissonlegsm1 .(see Figures 1 and 2')`.the,screw being rotatable' innuts m2 by means of. a vratchet actuatedI byga handle 'm3, ,The'scissor Llegs are pivotedVV at*k their `inner ends to the nuts, 1 at` their lower ends to theaxlebofthewheels 'b1 and at their upper .ends'to afro'd bifixe'd to the bracket b3. The axlebi'is'connectedto the bracket b3, by

inclination having been adjusted thewhole is lockedY in position 'by' any `suitable `mea-ns, e. g.,

slotted arms standing up *fromthe raxleib6 and lock nuts on the"rod*b7to lock'the slottedl ends of .thearms' to the rodb Y'Modifications' within the, scope of this vinvention are: :a collecting' brush "extending --across the full width iof a atslopi'ng surface; 'continuously instead of intermittently' rotating collectingV brushes; the use of'corduroyfelt orother suitable'ma- `terial vwrapped around a cylinder insteadofbrush bristles-a belt or similar contrivance with arough surface passing over a roller or the like.

In operation; the containerv (with thel collecting tanks below it when such tanks are used) is first filled by the flow of water through the brush. The normal gravitational flow of the ore and water fed in at the higher end of the machine, is converted into a reciprocating motion by the continuous to and fro motion of the sluice-box, which motion causes the minerals, owing to their greater specific weight, gradually to settle t the bottom of the mixture whilst the latter is flowing over the settling plane. The minerals, upon reaching the concentrating plane, and having previously settled to the bottom, are now gradually pressed together from the sides owing to the gradual slope and decreasing width of the concentrating plane, being assisted by the flow of water and the to and fro motion of the sluice-box, whilst the gangue spilled over the boundary walls of the concentrating plane is carried away rapidly by the flowing water over the higher fiat surface and away from the collecting brush, whereupon the process is repeated, commencing at the succeeding settling plane. Meanwhile the minerals continue their downward path towards the brush, continually pushing gangue away to the sides owing to the diminishing width and increasing depth of their volume, and thus arrive finally at the brush as concentrates.

The brush, being adjustable, is adjusted for the particular ore to be treated such that the height of the brush above the surface of the sluice-box is approximately equal to the depth or thickness of the mineral-concentration, thus allowing any overlying gangue to be washed over the brush and away to the next settling plane by the flow of the water. The minerals, on the other hand, cling to the rough surface of the brush which projects above the surface of the concentrating plane and has a width and depth substantially equal to those of the concentrated layer of minerals. Owing to its intermittent rotary motion, the brush allows settlement of the minerals including all the fines on said surface and thence carries the minerals below the surface of the sluice-box to deposit them into the container.

The to and fro motion of the container together with the rotating motion of the brush create a continual disturbance of the water in the container, which motion clears the concentrates from oi the brush allowing them to be shaken finally down into the container or tanks as the case may be, whence they are removed as already explained.

The distance between the brushes and the edges of the concentrating planes being adjustable by the vertical adjustment of the supporting plates of the brush locating radius arms, the brush at the end of the first concentrating plane can be so adjusted as to allow only concentrates say of minus 60 mesh to be carried down to the receiving tanks. All concentrates of plus 60 mesh would pass over the brush and be collected at the end of the second concentrating plane, the brush of which would be adjusted to remove only say minus 40 mesh the remainder passing over to be collected by the third brush which would be adjusted approximately equal to the largest mesh size of the valuable mineral content in the feed ore. Thus separate groups of concentrates of different mesh grading can be obtained on this one machine.

The necessity for previous classification of the feed after milling and before passing to the concentrating sluice-box is eliminated as any large size particles of gangue which should happen to pass on to the surface of the table cannot jam in nor choke the apertures due to the rotation of the brushes, and will consequently roll over the brushes and be washed away over the end of the table. Variations in the mesh of the valuable mineral content of the ore, however, are dealt with in the manner explained above.

We claim:

1. In a sluice box for concentrating minerals, the combination with a concentrating table having a slightly inclined bottom terminating at a horizontal discharge edge, of a cylindrical rotary brush having upstanding bristles, said brush being mounted adjacent said discharge edge with its axis extending parallel to said discharge edge belo-w the horizontal plane of the latter, means supporting said rotary brush for adjustment to several positions in which its peripheral surface projects to a greater or lesser extent above said plane, said supporting means including lever arms fulcrumed on an axis extending parallel to and adjacent said discharge edge, a platev extending over the rear portion of said rotary brush and being adjustable to various positions, whereby, for each adjusted position of said brush, the front edge of said plate may be positioned in contact with the peripheral surface of said brush approximately at the highest point thereof, and means for unidirectionally rotating said brush to cause movement of its peripheral surface adjacent said discharge edge in a direction substantially opposite to that 0f the flow of water coming from said concentrating table.

2. In a sluice box for concentrating minerals, the combination with a concentrating table having a slightly inclined bottom terminating at a horizontal discharge edge, of a substantially cylindrical rotary mineral collecting element, said element being mounted adjacent said discharge edge with its axis extending parallel to said discharge edge below the horizontal plane of the latter and its peripheral surface projecting above said plane and forming a gap with said discharge edge and means including lever arms fulcrumed on an axis extending parallel to and adjacent said discharge edge for adjustably supporting said rotary element, so that it may be selectively adjusted to several positions in which its peripheral surface projects to a greater or lesser extent above the horizonal plane of said discharge edge without changing the width of the gap between said peripheral surface, and said discharge edge.

3. In a sluice box for concentrating minerals, the combination with a concentrating table having a slightly inclined bottom terminating at a horizontal discharge edge, of a cylindrical rotary brush having upstanding bristles, said brush being mounted adjacent said discharge edge with its axis extending parallel to said discharge edge below the horizontal plane of the latter, and its peripheral surface forming a gap with said discharge edge, the solid core of said brush being disposed entirely below the horizontal plane of said discharge edge and some of its bristles proj ecting upwardly beyond said plane.

4. A sluice box, as claimed in claim 2, including a plate extending over the rear portion of said rotary elements and being adjustable to various positions, whereby, for each adjusted position of said rotary elements, the front edge of said plate may be positioned in contact with the peripheral surface of said rotary elements approximately at the highest point thereof.

FRANCIS JAIME WORMALD HOLT. AUGUST ULLMANN. HERBERT THOMAS HONNOR. 

